Wellhead seal device to seal casing

A wellhead seal device for sealing an annular space formed in a central bore extending through vertically aligned upper and lower wellhead members adjacent the rough outer wall of a tubular casing such that the casing extends through the lower wellhead member and has an upper end in the upper wellhead member, the wellhead seal device comprising:

• an annular metal sealing sleeve having an upper portion integral with a lower portion;
• the lower portion having an inner bore adapted to provide an inner seal to the casing and an outer surface adapted to provide an outer seal to the central bore of the lower wellhead member;
• the upper portion being configured to extend upwardly from the lower portion into the central bore of the upper wellhead member, the upper portion having an outer tapered surface adapted to form an external metal seal to a conical central bore section at a lower end of the upper wellhead member, and an inner surface adapted to be spaced from the casing in the upper wellhead member to form a sealing annulus;
• a metal seal ring having an outer conical surface and being adapted to fit around the casing within the sealing annulus supported by the lower portion adjacent the casing;
• a wedge ring adapted to fit around the casing above the metal seal ring and having an inner cam surface to engage the conical surface of the metal seal ring within the sealing annulus;
• a retaining ring adapted to be retained in and to close the sealing annulus of the upper portion around the casing above the wedge ring, the retaining ring forming a plurality of vertical threaded ports extending there through for alignment with the wedge ring;
• and
• a plurality of threaded seal energizing members adapted to be threaded through the threaded ports to push downwardly on the wedge ring such that the metal seal ring is compressed radially inwardly to form an internal metal seal to the casing and thus seal the sealing annulus, and to also transfer downward force to the lower portion to energize the inner and outer seals.

A method of sealing an annular space formed between an inner tubular member and an outer tubular member, comprising:

• providing an annular metal sealing sleeve having a lower portion and an upper portion, the upper portion forming a neck portion extending upwardly from the lower portion, the lower portion being adapted to be vertically supported in the annular space, and the neck portion having an inner surface adapted to be spaced from the inner tubular member to form an inner sealing annulus;
• installing the annular metal sealing sleeve in a vertically supported manner in the annular space;
• installing a first metal seal ring in a supported manner in the inner sealing annulus;
• applying a downward force within the inner sealing annulus such that the first metal seal ring is compressed radially inwardly to form an inner metal seal to the inner tubular member.

A method of sealing an annular space formed in a central bore extending through vertically aligned upper and lower wellhead members adjacent an outer wall of a tubular casing, the casing extending through the lower wellhead member and having an upper end in the upper wellhead member, the method comprising:

• providing an annular metal sealing sleeve having an upper sealing portion and a lower sealing portion, the lower sealing portion having an inner bore adapted to form an inner seal to the casing and an outer surface adapted to form an outer seal to the central bore of the lower wellhead member, and the upper sealing portion having an outer tapered surface adapted to form an external metal seal to a conical central bore section at a lower end of the upper wellhead member, and an inner surface adapted to be spaced from the casing in the upper wellhead member to form a sealing annulus to accommodate an internal metal seal to the casing;
• installing the metal sealing sleeve in the annular space of the lower wellhead member;
• installing a metal seal ring in a supported manner in the sealing annulus;
• applying a downward force within the sealing annulus such that the metal seal ring is compressed radially inwardly to form the internal metal seal to the casing, and to energize the inner and outer seals of the lower sealing portion;
• and
• connecting the upper wellhead member above the lower wellhead member such that the outer tapered surface of the upper sealing portion forms the external metal seal to the conical central bore section of the upper wellhead member.